Linux is a freely-distributable kernel and operating system that works
virtually the same as UNIX. Unlike all other available truly
UNIX-like operating systems (this means those that provide memory
protection and virtual memory), it is built from the ground-up from
scratch to comply with open standards. Currently, Linux complies with
virtually all of the POSIX.1 standard (the only completely
vendor-independent standard), and work is underway to finish work on
compliance with the System V Interface Definition (SVID) and other
commercially-established standards.

Linux was started in 1991 by Linus Torvalds, who at the time was an
undergraduate student in Computer Science at the University of
Helsinki in Finland. While Linus is no longer a starving college
student (he now works for Transmeta, a highly-secretive Silicon Valley company), he
continues to coordinate the work on the kernel and makes significant
contributions of his own, particularly on the Alpha and SMP (symmetric
multiprocessing) code. The names of many of the other people who have
contributed to the Linux kernel can be found in the CREDITS and MAINTAINERS files that are included with the
Linux kernel sources.

More of Linux's history (particularly the history of Linux/m68k) is
covered in the next section of the FAQ.

The Linux kernel is vaguely equivalent to the Kickstart under AmigaOS.
It provides basic services to the operating system, but that's about
it. Unlike AmigaOS, it requires at least one other program to launch
(a shell &lsqb;command line interpreter&rsqb; or a special program
called init). Without another program,
you'll never even get to a command prompt.

The Linux operating system is a collection of programs (such as
interpreters, shells, utilities, applications, and daemons) and
libraries that facilitate user interaction with the system. Much of
the Linux operating system is derived from the Free Software
Foundation's GNU project and the University of California at Berkeley
Source Distribution of Unix (BSD). The Linux OS also includes
software from other sources, some of which was written specifically
for Linux.

For the most part, I use the term Linux as the generic term for both
the operating system that most Linux users use and to refer
specifically to the kernel. Others would use "GNU/Linux", or a
distribution name (e.g. "Red Hat Linux", "Slackware Linux", or
"Debian GNU/Linux"), for the operating system, reserving "Linux"
strictly for the kernel. Suffice it to say it's not worth the effort
to try to convince me to adopt this alternative terminology (you can
start the GNU/Linux/m68k FAQ if you like :-).

Where the distinction between one meaning of Linux and another is
unclear, I apologize in advance.

MkLinux is a
project sponsored by Apple (in collaboration with the Open Group, née
the Open Software Foundation) to build a Microkernel-based Linux
kernel for PowerPC (and some other) systems.

Linux/m68k is a
project to build a monolithic Linux kernel for 680x0 systems. It has
no connection with Apple or the OG/OSF (as a matter of fact, Apple,
unlike many other manufacturers, has been downright unhelpful with the
m68k Linux port).

Unfortunately, the use by some of the term "MacLinux" has added to the
confusion and made a lot of people think that MkLinux and Linux/m68k on the
Macintosh are the same project. They aren't. Not even close.